178 



HISTORY OF THE VEGETABLE KINGDOM 



whicli belong to MonadelpUa, are said to be 

 triandrous, tetrandrous, pentandrous, or poly- 

 androus, according as they contain tliree, four, 

 five, ten, or a greater number of stamina united 

 by their filaments into a single body. In Dia- 

 delphia and Polyadelphia, the same method is 

 followed, the orders having the names of the 

 first classes of the system. 



Syngenesia, the nineteenth class of the sexual 

 system, is one of the most extensive. In fact, 

 the synantherese or syngenesian plants foi-m 

 about the twelfth part of all the known vegeta- 

 bles. It was therefore necessary to divide this 

 class into several orders, to facilitate the inves- 

 tigation of its different species. Linnaeus, ac- 

 cordingly, instituted six orders. But here the 

 number of the stamina could not be employed 

 as the basis of these subdivisions, it being almost 

 invariably five; for which reason he derived the 

 characters of the orders from the structure of 

 the little flowers which constitute the assem- 

 blages known by the name of compound flowers; 

 for in consequence of constant abortions, there 

 occur along with the hermaphrodite flowers, 

 male flowers, female flowers, and even sometimes 

 perfectly neutral flowers. LinnsEus, whose poeti- 

 cal fancy is observable in all the names which 

 he imposed upon the different classes and orders 

 of his system, looked upon these associations 

 and mixtures of flowers as a kind of poli/gamy. 

 This name he accordingly gave to each of the 

 six orders of syngenesia, adding to it a distinc- 

 tive epithet. The following are their characters. 



Order 1. Polygamia ceqtialis. AU the flowers 

 are hermaphrodite, and in consequence are all 

 equally fertile; as in thistles and goatsbeards. 



Order 1. Polygamia superflua. The flowers 

 of the disk are hermaphrodite, those of the cir- 

 cumference female; but both kinds furnish per- 

 fect seeds, as in wormwood and tansy. 



Order 3. Polygamia frustranea. The flowers 

 of the disk are hermaphrodite and fertile, those 

 of the circumference neutral or female, but 

 sterile in consequence of their stigma, and there- 

 fore entirely useless; whereas in the preceding 

 order they were only superfluous, as the knap- 

 weeds and sunflowers. 



Order 4. Polygamia necessaria. The flowers 

 of the disk are hermaphrodite, but sterile, in 

 consequence of an imperfect formation of the 

 stigma; those of the circumference are female, 

 and fecundated by the pollen of the former. 

 In this case, they are therefore necessary for the 

 preservation of the species : the marigold is an 

 example. 



Order 5. Polygamia segregata. All the flowers 

 are hermaphrodite, and placed close together, 

 but are separately contained each in a small 

 involucre of its own, as in the genus Echinops. 



Order 6. Polygamia monogamia. The flowers 

 are all hermaphrodite, but they are simple, and 



are separated from each other, as in the violet, 

 lobelia, balsamine. 



The last order, as may easily be seen, has no 

 affinity to the rest, possessing nothing in common 

 with them but the union of the stamina by 

 their anthers. 



In Gynaniria, the twenty-first class of the 

 sexual system, there are four orders which are 

 derived from the number of the stamina. Thus 

 we have Gynan/lria monandria, as in the genera 

 Orchis and Ophrys; Oynandria diandria, as in 

 Cypripedium; Oynandria hexandria,2& in Aris- 

 tolochia; Gyandria polyandria, as in Arum. 



Mmuecia and Dicecia present in some measure 

 a union of all the modifications which we have 

 remai'ked in the other classes. Thus Moncecia 

 contains monandrous, triandrous, decandrous, 

 polyandrous, monadelphous, and gynandrous 

 plants. Each of these varieties is used for the 

 establishment of a distinct order in this class. 



Diacia contains a still greater number of 

 varieties, the characters of wliich being the same 

 as those of some of the classes previously es- 

 tablished, are employed as desiguative of the 

 orders. 



The twenty-third class, Polygamia, which 

 contains plants with hermaphrodite flowers and 

 unisexual flowers intermingled, whether on the 

 same individual, or on two or three distinct in- 

 dividuals, has, in accordance with these circum- 

 stances, been divided into three orders. 



1. Monmcia, in which the same individual 

 bears monoclinous flowers, and declinous flowers; ' 



2. Dioecia, in which there are hermaphrodite 

 flowers on one individual and unisexual flowers 

 on the other; 3. Triwcia, in which the species 

 is composed of three individuals, one bearing 

 hermaphrodite flowers, another male flowers, 

 and the third female flowers. 



Cryptogamia, the twenty-fourth and last class, 

 is divided into four orders: 1. Ferns; 2. Mosses; 



3. Algae; 4. Fungi. 



TABLE OF CLASSIFICATION. 

 - CLASSES. ORDERS. 



1. MONANDRIA. 



Mono^ynia 



Plants of one 

 stamen and one or 

 two pistUs. 



2. DIANDRIA. 



The Britisli 

 plants in tliis 

 class have two 



stamensandone ^""^^^-^^ (,2 Digynia 

 or two pistils 

 the flowers are larger and 

 their parts more oistinct 

 than in the fii-st class. 

 3. TRIANDRIA. 



Plants of three 

 stamens, and one, 

 two, or three pis- 

 tils. Besides a 

 considerable number of 

 very beautiful plants, and 

 a few useful in medicine, 

 this class contains the 

 most important natm-al 

 family in the whole circle 

 of vegetation— the Grami- 

 nea. 



^ 2 Digynia 

 C 1 Monogynia 



1 Monogynia 



2 Digynia 



-3 TrigyTlja 



